Evolutionary biologists believe that speciation, the formation of a new species, often begins when some kind of physical barrier arises and divides a population of a single species into separate subpopulations. Physical separation between subpopulations promotes the formation of new species because once the members of one subpopulation can no longer mate with members of another subpopulation, they cannot exchange variant genes that arise in one of the subpopulations.
1. The word “promotes” in the passage is closest in meaning to
Why does the professor mention medieval Europe?
A. To point out an important difference Europe and the United States.
B. To introduce a reason that the first European settlers moved to North American.
C. To indicate the style of community planning followed by in the northern colonies.
D. To point out that urban planning has changed considerably since the medieval period.
Some schools require students to take part in community service activities after school. Which of the following volunteer activities do you think is the best activity for students?
1. planting flowers in the community;
2. doing clean-ups in the garden;
3. recycling waste;
Preparation Time: 15 Seconds
Response Time: 45 Seconds
If you are selecting a leader for a student organization or a club, do you agree or disagree that honesty is the most important thing to consider in deciding whom to vote for?